Frequently within the context of providing inmate telephone services, parties who are not confined request that their numbers be blocked from future call attempts from those who are confined. While it is always an option for the called party to simply not answer, not accept the call upon answering, or to immediately hang up, for many reasons it is more desirable to most parties that the call never be allowed to perpetuate in the first place and to inform the inmate that calls are not permitted to this number. There are a number of reasons why these unwanted calls may initially occur. For example, inmates often call random numbers in an attempt to talk to anyone who will accept the call, oftentimes then encouraging the called party to connect them to yet another party via 3-way or conference calling features. Other times, the inmates are deliberately attempting to harass, annoy or intimidate the called party. Still other times, a called party may wish to block the (typically collect) calls due to budgetary constraints that are not being respected by the calling inmate. Many other valid reasons are commonly given for wishing to have the call attempts blocked, and it is typically a requirement of the provider of the telephone service to provide a means for accomplishing these blocks in as simple and automated fashion as possible.
Historically, inmate phone service providers have accomplished the processing of these blocks in a variety of ways. One common method is that the called party may submit a request to the confinement facility, who will then relay the request to the phone service provider, who will then process or “load” the block into the telephone system, preventing future call attempts. Another common method is that the called party may call the telephone service provider directly and speak with a customer service representative, requesting that the number be blocked. Both of these methods are labor-intensive, as they require the involvement of multiple persons, and also provide no security against one person attempting to block another person's phone number, such as commonly occurs in the case of a suspicious spouse or a jilted ex-spouse, for example. Yet another common method of processing these block requests is that upon receiving the call from the inmate, the called party is instructed to simply press a specified DTMF digit to indicate that they wish to have their number blocked. This method, while improving on the efficiency of the process, also leaves open some potential flaws for exploitation and is highly prone to unintentional blocks which must then be reversed upon eventually discovering that they occurred. For example, it is quite common for parties to use social engineering and deception to convince a customer service rep to temporarily activate call-forwarding from one person's phone to another. In this context, a party could have an intended called party's phone number forwarded to their own, and then, upon receipt of an inmate phone call, block the number such that it appears to the inmate that the calls are unwanted, and it appears to the intended called party that no calls have been attempted. Another weakness of this method is the ease by which a called party may unintentionally block their own number by way of an errant key press, and further, that there is no simple recourse or confirmation once this has been done other than to call the confinement facility or the phone service provider's customer service and find out that the number is indeed blocked, and then try to convince them that it was an accident, while having no audit trail available for verification. Yet another weakness of this method is that in the case where there are multiple persons who potentially may answer the called number, there is no means provided for documenting who performed the blocking action, or who the authorized party is, should a dispute arise between the parties regarding who has the authority to perform such actions, or to unblock the number, as is frequently observed in cases involving parents and children.